Portable pneumatic edge crimping tool for sheet metal



3mm 1, 1947. c. R. SPRINKLE 2,414,173

PORTABLE PNEUMATIC EDGE CRIMPING 'I'OO L FOR SHEET METAL Filed Sept. 28, 1943 YIIIIII/II/IIIIII/llll INVENTOR l'ho leS flq rinfiie WKM Patented Jan. 14, 1947 PORTABLE PNEUMATIC EDGE CRDIPING TOOL FOR SHEET METAL Charles R. Sprinkle, Stratford, Comm, asslgnor to United Aircraft Corporation, East Hartford, Conn., a corporation of Delaware Application September 28, 1943, Serial No. 504,119

' 11 Claims.

1 This invention relates to a sheet metal working tool, and more specifically to a portable pneu I matic crimping tool.

An object of the invention is the provision of a power operated edge shaping tool adapted to be held in the hand of an operator and moved along the edge of a sheet of metal to bend or bend and stretch the edge portion of the sheet as required preparatory to securing the sheet along its edge to an underlying surface.

Another object of the invention is the provision of a tool of this kind for subjecting the edge of the sheet to repeated blows from a hammer and.

in which the hammer action can be increased in speed and in power to stretch the edge portion of the sheet in varying degrees as required to fit the sheet to curved underlying surfaces having varying degrees of curvature.

A further object of the invention is the provision of a tool of this general character which is easily adjustable to different kinds of work, which can be applied as an attachment to a standard riveting gun, and one which does not require great skill in operation.

These and other objects of the invention will be apparent from the following detailed description of a preferred embodiment thereof, considered in connection with the accompanying drawing submitted for purpose of illustration only, and not intended to define the scope of the invention,

reference be ng had for that purpose to the claims appendant hereto.

. In the drawing,

Fig. l is a side elevation partly in section showing the tool in operation on the edge of a metal sheet:

Fig. 2 is a front view of the tool of Fig. 1; and

Fig. 3 is a perspective view of the forming memher.

The edge shaping tool illustrated for the purpose of disclosing the invention comprises a usual pneumatic hammer, or riveting gun, generally indicated at A, a frame or body portion B formed from a block of metal and an inverted generally U-shaped forming member C.

The gun A is preferably a standard fast-hitting pneumatic riveting gun including a barrel portion In having an externally threaded end l2 and an integral angularly related handle l4. Air is supplied through an air connection It from a usual flexible hose to effect reciprocation of a striking member l8 having an enlarged striking head IS, a usual air adjustment I! being provided at the end of the handle.

The body portion, or frame, B is generally rec- 2 tangular and is provided with a centrally located and inclined threaded aperture 20 to receive the threaded end l2 of the riveting gun, a set screw 22 being provided to lock the body portion B to the end of the gun barrel in the desired angular relationship. The front end of the body portion B is also provided with a groo 0 e 4 which extends transversely across the front face thereof and intersects the plunger aperture 210, the groove extending a substantial distance into this aperture as indicated in Fig. 1. I

It will be evident from Fig. lthat the groove 24 is located. below the horizontal center line of the body portion or block B, thus forming in effect a lower forwardly protruding jaw 28 having its lower corner chamfered to form an oblique surface 28. The jaw 28 is cut away at opposite side faces thereof to receive the parallel sides 30 of the forming member C, these sides likewise being chamfered to provide oblique surfaces: flush with the oblique surface 28. A bolt 32, which extends through apertures 3| in the sides 30 of the forming member and through an aligned aperture flu in the jaw 28, secures this member fixedly to the law with the connecting portion 34 thereof overlying the lower side wall of groove 24. The portion 34 of the forming member has a forward sheet guiding surface 36 parallel to the upper side wall of groove 24 and also has an anvil surface 38 inclined downwardly and rearwardly from the surface 38 which, as here shown, is disposed parallel to the bottom or striking surface 40 of striking head IS.

The forming member C is also provided with a pair of laterally spaced stop members 42 upstanding from the rear oblique surface thereof on opposite sides of the aperture 20, the front faces 44 of these members being adapted to engage the edge of a sheet W to be shaped and limit its movement into the groove 24. It will be noted from Fig. 3 that the oblique anvil surface 38 extends along the length of the forming member in front of the stops 42 as indicated at 46, these surfaces 48 finally merging into the curved upper ends of the sides 80. The stop members 42 are 3 1 and 2 the rolls 50 project slightly into the groove 24 so that a sheet located in the groove 24 is guided on its upper surface out of contact with the upper wall of groove 24 by the'antifriction rolls and on its lower surface by the uiding surface 36 which is direc.ly beneath the rolls 50.

A handle 56 is provided on the back of the body portion B substantially in the same horizontal planes as the sheet W. As shown, the handle 56 has a screw-threaded stud 58 fixed therein which is threaded into a suitable recess in the body portion B. Preferably the handle [4 of the riveting gun and the handle 56 are both rearwardly extended in parallel relation, 50 that by grasping the handle l4 in one hand and handle 56 in the other the operator is able to guide the tool smoothly along the edge of the sheet W.

In the operation of the device, the tool is placed on the edge of the sheet W with the edge of the latter abutting the stop surfaces 44. It will be understood that a suitable forming member C has ing surface for holding a sheet in said groove against said guiding surface.

2. A portable edge shaping tool adapted to be moved along the edge of a sheet to be shaped including a rigid body member comprising a block having a lateral sheet receiving kerf therein, the upper and lower walls and the end'wall of which are formed by said rigid body member, a forming member on one side wall of said kerf having a guiding surface parallel with the plane of the sheet to be shaped and an anvil surface oblique with respect to the plane of said sheet, spaced stops projecting into said kerf for engaging the inserted edge of the sheet to limit the entry of the sheet into said kerf, a passage in said block normal to said anvil surfaceand between said stops, a pneumatic hammer carried by said body portion including a pneumatically actuated striking member reciprocable in said passage and having a striking face substantially parallel with 4 said anvil surface for engaging a continuous edge the plane of the sheet, as determined by the angle oi the anvil surface 38, so that when the sheet is secured by rivets or by spot welding along its edge to an underlying surface the edge will ciprocating striking member I8, a stretching ofv the metal in the edge portion of the sheet results, providing in effect a crimping of this edge as is required when the sheet is to be attached to a curved surface. By adjusting the member I1 to vary the air pressure acting to reciprocate the striking member l8, it is possible to vary the stretching 0r crimping action, as required to fit the edge of the sheet metal to surfaces of widely varying curvatures, i

It will be evident that as a result of my improvement I have provided an edge shaping tool which is portable and which will perform a wide variety of edge shaping operations with great facility. Thus by varying the pressure of the air applied to'the hammer, the operator is able to bend the edge slightly or by applying greater pressure to actually stretch the edge portion to prepare the sheet for attachment to variously curved surfaces. Also by changing the forming member- C the tool can be quickly adapted to work on different gauges of metal. It will also be-evident that forming members may be substituted having anvils of varying angularity.

While I have shown and described one embodiment which my invention may assume in practice, it will be evident that various changes may be made in the form and arrangement of the parts without departing from the scope of the invention as defined in the following claims.

What I claim and desire to secure by Letters Patent is as follows:

1. A portable edge shaping tool adapted to be moved along the edge of a sheet to be shaped including a body portion having a groove therein portion of the sheet between said stops, said stops being sufliciently spaced and said striking face being sufficiently extensive to contact a substantial length of the edge portion of the sheet being shaped at each engagement of said striking member therewith.

3. A portable edge shaping tool adapted to be moved along the edge of a sheet to be shaped ineluding a rigid body member comprising a block having a lateral sheet receiving kerf therein the upper and lower walls and the end wall of which are formed by said rigid body member, a handle secured to said block and projecting laterally therefrom in the plane of said kerf and on the opposite side of said block from said kerf, a forming member on one major wall of said kerf having an anvil surface oblique to the plane of the sheet in said kerf, spaced stop means on said member for limiting the entry of the sheet into said kerf while leaving a substantial length of the edge exposed between said stops, a passage in said block normal to said anvil surface and between said stops, an air hammer carried by said body portion having pneumatically actuated impact means for stretching the edge of the sheet between said stops by rapidly repeated blows thereon including a striking member reciprocable in said passage between said stops having a striking face cooperating with said anvil surface for engaging the continuous length of said edge'portion of the sheet between said stops, said hammer having a handle disposed in generally parallel relation with and spaced from said first mentioned handle, and means for varying the impact of said striking member on the edge portion of the sheet including an adjustable member on said hammer handle.

4. A portable edge shaping tool adapted to be moved along the edge of a sheet to be shaped in. cluding a body portion having a groove therein to receive the edge of the sheet, a handle secured to said body portion in the vicinity of said groove and projecting laterally therefrom on the opposite side from said groove-an anvil on one side face cooperating with the face of said anvil, and a pair of spaced anti-friction rollers carried by said body portion on opposite sides of said striking member and having peripheral portions protruding into said groove from the opposite said anvil. v

5. A power edge shaping tool including, in combination, a frame having a groove in its front end, a power hammer carried by said frame including a striking member reciprocable transversely of said groove and having a, striking face, an inverted U-shaped forming member having its parallel sides detachably secured to said frame and having its connecting portion overlying the lower side wall of the groove, said connecting portion having an upper sheet guiding portion on its upper face parallel with the upper side wall of ,the groove and having an anvil portion oblique relative thereto adjacent the bottom of the groove and generally parallel with said striking face, and anti-fricti0n means carried by said frame and protruding into said groove opposite the sheet guiding portion of said forming member.

6. An attachment for a riveting hammer comprising a block adapted to be connected to the end of a hammer barrel and having a passage therein for reciprocation'of the impact member of the hammer, a groove in'said block intersecting said passage, an anvil having a face oblique to the planes of said groove and located at tile bottom of said passage, and guiding and positioning means in said groove for locating the edge of a metal sheet relative to said oblique face inside of said groove site sides of said passage and removable with said forming member.

9. An attachment for a riveting hammer comprising a block adapted to be connected to the end of a hammer barrel and-having a passage therein for reciprocation of the impact member of the hammer, a transverse groove in the front of said' block communicating with said passage, a forming member removably secured to said block on a face of said groove having a sheet guiding portion on the lower face of said groove parallel with the upper side wall thereof and at the front of'said groove and. an oblique anvil portion at the rear of said groove, said member also having laterally spaced stops located on opposite sides of said passage and projecting upwardly into said groove from said anvil portion, a pair of rollers carried by said block in front of said stops and projecting into said groove opposite said sheet guiding portion, said forming member having depending ears for attachment to said block and said stops having portions cut away to receive said rollers and permit said member to be withdrawn at the front of said block.

eluding two stops in the rear portion of said groove on opposite sides of said impact member a and two rollers journalled in said block and hav-' ing peripheral portions thereof projecting into 1 said groove in front of said stops.

'7. An attachment for a riveting hammer comprising a block adapted to be connected'to the .end of a hammer barrel and having a passage therein for reciprocation of the impact member of the hammer, a transverse groove in said block communicating with said passage, a forming member disposed on a side wall of said groove at the bottom of said passage having a sheet guiding portion adjacent the mouth of said groove and parallel with the side walls of said groove and an adjoining anvil portion oblique relative thereto extending farther into said groove; and means including anti-friction rollers journalled in said'block opposite saidsheet guiding portion and having peripheral portions thereof extending into adjacency to said portion.

B. An attachment for a riveting hammer comprising a block adapted to be connected to the end of a hammer barrel and having a passage therein for reciprocation of the impact member of the hammer, a transverse groove in the front of said block communicating with said passage, a forming member removably securedto said block having a sheet guiding portion on the lower face of said groove parallel with the upper side wall thereof and at the front of said groove and an oblique anvil portion at the rear of said groove, said forming member also having laterally spaced sheet engaging stops thereon projecting upwardly into said groove from said anvil portion on oppo- .10. The combination with a portable'body and I a power operated percussive type reciprocating hammer mounted in the body and having an impact face at its outer end. of a frame rigidly supported from the body, an anvil member on the frame in opposed relationtothe driving face of the hammer, having a substantially flat abutment face rigid with the frame and angular with relation to the axis of. the hammerforfiengaging a portion of the flat sheet spaced inwardly from its edge and positioning the frame at a predetermined angle relatively to the plane of the sheet when the flat anvil is held coplanar with the sheet, and a corner at the inner end of the abutment on which the portion of the sheet between its edge and the abutment face will be bent by the hammer to an acute angle in relation to the plane of the sheet, the faces of the hammer and abutment and the bending corner being extended transversely of the axis of the hammer for sliding movement along the edge of the sheet so that the percussive blows of the hammer will rapidly bend a continuous uniformly angled marginal flange on the sheet as the frame is moved along the margin of the sheet.

11. The combination with a portable body and a power operated percussive type reciprocating hammer mountedin the body and having a fiat impact face at its outer end, of a frame rigidly supported from the body, an anvil member on the frame in opposed relation to the impact face of the hammer, having a substantially flat abutment face rigid with the frame and angular with relation to the axis of the hammer for engaging a portion of a flat sheet spaced inwardly from its edge and positioning the frame at a predetermined angle relatively to the plane of the sheet when the flat anvil is held against one "face of the sheet, and a corner at the inner end CHARLES R. SPRINKLE. 

